NMP

The basis of the nuclear microprobe (NMP) is a source of energetic ions from a particle accelerator. These... 

The quantitative imaging capability of the NMP is one of the major strengtiis of the teclmique. The advanced state of the databases available for PIXE [21, 22 and 23] allows also for the analysis of layered samples as, for example, in studying non-destmctively the elemental composition of fluid inclusions in geological samples. 

The application of RBS is mostly limited to materials applications, where concentrations of elements are fairly high. RBS is specifically well suited to the study of thin film stmctures. The NMP is usefiil in studying lateral inliomogeneities in these layers [30] as, for example, in cases where the solid state reaction of elements in the surface layers occur at specific locations on the surfaces. Other aspects, such as lateral diffusion, can also be studied in tluee-dimensions. 

Figure Bl.24.16. An example of the applieation of the PIXE teelmique using the NMP in the imaging mode. The figures show images of the eross seetion tlirough a root of the Phaseolus vulgaris L. plant. In this ease the material was seetioned, freeze-dried and mounted in vaeuiim for analysis. The seales on the right of the figures indieate the eoneentrations of the elements in ppm by weight. It is elear that the transports of the elements tlirough the root are very different, not only in the eases of the major elements Ca and K, but also in the ease of the traee element Zn.

Under different conditions [PdfOAcj2, K2CO3, flu4NBr, NMP], the 1 3 coupling product 86 with 4-aryl-9,10-dihydrophenanthrene units was obtained. The product 86 was transformed into a variety of polycyclic aromatic compounds such as 87 and 88[83], The polycyclic heteroarene-annulated cyclopen-tadicnc 90 is prepared by the coupling of 3-iodopyridine and dicyclopentadiene (89), followed by retro-Diels Alder reaction on thermolysis[84]. 

The coupling of the enol triflate 703 with the vinylstannane 704[397] has been applied to the synthesis of glycinoeclepin[576]. The introduction of a (Z)-propenyl group in the / -lactam derivative 705 proceeds by use of tri-2-furylphosphine[577]. However, later a smooth reaction to give the propenyl-iactam in 82% yield was achieved simply by treating with Pd(OAc)2 in NMP or CH2CI2 for 3-5 min without addition of LiCI and the phosphine ligand[578]. 

Fig. 33. Correlation of NMP uptake with polymer T for a series of 24 different polymeric films. All films were heated after coating at 100°C for 300...

Arosolvan process. A/-meth5i-2-pyrr a polar mixing compo-nent, either NMP—glycol, 60 vertical multi-stage the quantity of mix-ing... 

Lurgi oHdi-none (NMP) water (12—20) or monoethyl-ene glycol (40—50 wt %) must be added to the NMP to increase the selectivity and to decrease the boiling point of the solvent the NMP—water proc-esses use pentane countersolvent NMP—water, 35 mix-ter—setder, 24—30 stages, up to 8 m in diameter component required depends on the aromatics content of the feed... 

Suspension- and emulsion-polymerized PVDF exhibit dissimilar behavior in solutions. The suspension resin type is readily soluble in many solvents even in good solvents, solutions of the emulsion resin type contain fractions of microgel, which contain more head-to-head chain defects than the soluble fraction of the resin (116). Concentrated solutions (15 wt %) and melt rheology of various PVDF types also display different behavior (132). The Mark-Houwink relation (rj = KM°-) for PVDF in A/-methylpyrrohdinone (NMP) containing 0.1 molar LiBr at 85°C, for the suspension (115) and emulsion... 

New heat-resistant polymers containing -iiitrophenyl-substituted quinoxaline units and imide rings as well as flexible amide groups have been synthesi2ed by polycondensation reaction of a dianainoquinoxaline derivative with diacid dichlorides (80). These polymers are easily soluble in polar aprotic solvents with inherent viscosities in the range of 0.3—0.9 dL/g in NMP at 20°C. AH polymers begin to decompose above 370°C. 

A polyester backbone with two HFIP groups (12F aromatic polyester of 12F-APE) was derived by the polycondensation of the diacid chloride of 6FDCA with bisphenol AF or bisphenol A under phase-transfer conditions (120). These polymers show complete solubkity in THF, chloroform, ben2ene, DMAC, DMF, and NMP, and form clear, colorless, tough films the inherent viscosity in chloroform at 25°C is 0.8 dL/g. A thermal stabkity of 501°C (10% weight loss in N2) was observed. 

The preparation of high molecular weight PPT in HMPA/NMP shows a strong dependence of inherent viscosity on reactant concentrations. In 2 1 (by volume) HMPA/NMP, the highest inherent viscosity polymer is obtained when each reactant is present in concentrations of ca 0.25 M higher and lower concentrations result in the formation of polymer of lower inherent viscosities. A typical procedure is as foUows 1,4-phenylenediamine, HMPA, and NMP are added to an oven-dried resin ketde equipped with a stirrer and stirred for ca 15 min with cooling to — 15°C, foUowed by the addition of powdered terephthaloyl chloride to the rapidly stirred solution. The reaction mixture changes to a thick, opalescent, paste-like gel in ca 5 min. 

An alternative polymerization process utilizes a slurry of calcium chloride in NMP as the polymerization medium. The solubiHty of calcium chloride is only 6% at 20°C however, the salt continues to dissolve as conversion of monomers to polymer proceeds and calcium chloride/polyamide complexes are formed. Polymer molecular weight is further increased by the addition of /V, /V- dim ethyl a n i1 in e as an acid acceptor. This solvent system produces fiber-forming polymer of molecular weights comparable to that formed in HMPA/NMP. 

Technora. In 1985, Teijin Ltd. introduced Technora fiber, previously known as HM-50, into the high performance fiber market. Technora is based on the 1 1 copolyterephthalamide of 3,4 -diaminodiphenyl ether and/ -phenylenediamine (8). Technora is a whoUy aromatic copolyamide of PPT, modified with a crankshaft-shaped comonomer, which results in the formation of isotropic solutions that then become anisotropic during the shear alignment during spinning. The polymer is synthesized by the low temperature polymerization of/ -phenylenediamine, 3,4 -diaminophenyl ether, and terephthaloyl chloride in an amide solvent containing a small amount of an alkaU salt. Calcium chloride or lithium chloride is used as the alkaU salt. The solvents used are hexamethylphosphoramide (HMPA), A/-methyl-2-pyrrohdinone (NMP), and dimethyl acetamide (DMAc). The stmcture of Technora is as follows ... 

The nitro alcohols in Table 1 are manufactured in commercial quantities however, three of the five of them are used only for the production of the corresponding amino alcohols. 2-Methyl-2-nitro-l-propanol (NMP) is available as the crystalline soHd or as a mixture with siHcon dioxide. 2-Hydroxymethyl-2-nitro-1,3-propanediol is available as the soHd ( 9.15/kg), a 50% solution in water ( 2.33/kg), a 25% solution in water ( 1.41/kg), or as... 

---